Detection of 14q32 rearrangements in multiple myeloma, using simultaneous FISH analysis combined with immunofluorescence

Abstract

BACKGROUND: 14q32 rearrangement has been identified as a recurrent hotspot of translocations in multiple myeloma (MM). The Fluorescence Immunophenotyping and Interphase Cytogenetics as a tool for the Investigation of Neoplasms (known as FICTION technique) for evaluation of chromosomal changes in MM. The aim of this work is to detect 14q32 rearrangement, using FICTION technique, on archival bone marrow (BM) slides of MM patients, and to study its prognostic value. METHOD: This study was conducted at Ain Shams University Hospital. The FICTION technique, which uses CD138 and dual color, and the break-apart 14q32 rearrangement probe, was performed on archived smears of BM slides for 50 MM patients at the time of diagnosis. RESULTS: A significantly higher percentage of cases were positive for 14q32 rearrangement by FICTION (32%) compared to fluorescence in situ hybridization (FISH) (12%) (p = 0.04). Cases positive by FICTION for the rearrangement were designated as Group A, while negative cases were designated as Group B. Significantly lower Hb and CRP levels were found among Group B when compared to Group A patients (p = 0.001 and 0.01, respectively). Serum albumin level and Bence Jones protein (BJP) significantly affect overall survival (OS) (p = 0.01, 0.007, respectively). However, a statistically non-significant shorter mean survival time was found in positive cases through FICTION versus negative cases. CONCLUSION: FICTION technique provides a sensitive tool for establishing clonal plasma cells (PC) infiltration of BM aspirates, and is amenable for use on archived as well as fresh smears.